Valve for steam-pumps



2 SheetsSheet 1.

(No Model.)

J FARLEY VALVE FOR STEAM PUMPS.

Patented Sept. 18, 1894.

m WW w W f m II! I] tfl 1w .m J 9 9 ,5 f

2 Sheets--.Sheet 2.

'(No Model.) I J. PARLBY.

VALVE FOR STEAM PUMPS. No. 526,149. Patented Sept. 18, 1894.

I/La:

Ryan 1 02".

Z z zz-eys as,

, lzmea 1 2/7263 class generally employed in connection with UNIT DSTATES :ATENT OFFICE."

JAMES FARLEY, OF \VAUKESHA, WVISGONS IN.

VALVE FOR STEAM-PUMPS.

SPECIFICATION forming part of Letters PatentNo. 526,14 9, datedSeptember 18, 1894.

Application filed Mar h 6, 1894. sen'al No. 502,488- (No model.)

To all whom it may concern.-

Be itknown that 1, JAMES FARLEY, a citizen of the United States,residing at Wankesha, in the county of Waukesha and State of Wisconsin,have invented a new and useful Improvementin Valves for Steam-Pumps, ofwhich the following is a specification.

My invention relates to valve-motion of improved construction for use inconnection with fluid-actuated pumps generally; and it relates moreespecially to improved valvemotion for use in connection with thesteamactuated pumps of air compressors, of the the air-brake systems ofrailway trains.

My object is to provide a valve-motion, of an improved construction,which will overcome dead points, in the movement of the valve whichcontrols the ingress and egress of steam which actuates the main piston;which will operate automatically to cushion the steamcylinder piston atthe end of each stroke to maintain the proper clearance and preventpounding or jarring of the parts; and it is my object further to providea valve-motion which will be of a simple and durable construction andparticularlyeffective in its operation. l i

In the drawingsFigure l isa vertical central section of asteam-cylinder, and valvegear for alternately directing steam to andexhausting it from the opposite sides of the steam-cylinder piston; Fig.2, a plan section taken on line 2 of Fig. 1; and Fig. 3, an end view ofa slide-valve.

A is a steam-cylinder formed with an annular shell or body-portion Aprovided with heads A and A The cylinder-head A forms a casing for thevalve-gear or valve-motion, to which my invention relates, and thecylinder head A may be an integral part of a separating or center pieceA which is formed at its opposite end integrally, as usuallyconstructed, with one of the cylinder-heads of an air-compressor.

As my invention relatesonly to the construction and operation of theparts which control the ingress of steam to the cylinder and its exhausttherefrom, it isnot thought necessary to illustrate the air-compressor,which may be of any desired form.

In the cylinder Ais a piston B on one end of a stem B which worksthrough a stnffingbox y in the cylinder-head A In practice thepiston-stem B extends through a stuffingbox in one of the heads of anair-compressor cylinder and connects with thepiston therein.

Extending centrally through the head or casing A is an opening, which isclosed by a screw-cap a1, and affords a circular chamber or auxiliarycylinder t, provided with a bushing t, and a circular steam-chamber s,of smaller diameter than the chamber t, and provided with a bushing s.

In the bushing s is an inlet port 1' communicating, through a passage rin the shell of the casing A with a steam-induction pipe O. Cored in thecasing, and extending from the passage 'r', is a branchpassage g whichcommunicates with the chambert through ports g C12, in the bushing t,and in the relasteam-cylinder exhaust-pipe 19 which may extend, inpractice, to the smoke-box of the locomotive. Above and below the port10 are cylinder ports m n, respectively,in the bushing s and in therelative positions shown. The port n communicates with a cored-passageat extending to the upper side of the main-cylinder A above themain-piston B; and the port m communicates with a coredpassage mextending to the lower side of the main-cylinder A, below themain-piston B.

D is a valve-stem extending centrally of the chambers A, s and t. At theupper end of the stem is an auxiliary-piston l fitting and sliding inthe auxiliary-cylinder 2? against the bushing t. The piston Z isconstructed to perform the functions of I a piston and slide valve, andits side adjacent to the port q? is enlarged and provided with a cavityZ to afford a slide-valveof the D type, as shown. The piston Z may beprovided with the usual packing-rings Z and the cavity Z may extendbeneath the rings, as shown.

seems ment of the piston, impinge against the upper and lower parts ofthe chamber 15, to limit the traverse of the piston, in oppositedirections, as hereinafter described. On the stem D, in the chamber 8,and fitting and sliding against the bushing s are balanced pistons loand k, of equal area, and working, respectively, in the upper and lowerparts of the chamber 5. Between the pistons It) and 7c the stern D issquared, or otherwise rendered noncircular; and fitting over the squaredportion of the stem is a main slide-valve D, of the D type, having acavity 2', and provided at opposite ends with lugs 'Z. The slide valveD, with its lugs, extends short of the distance between pistons 70 70,whereby in the movement of the said pistons, as hereinafter described,they will have movement, to a limited extent, independent of theslide-valve. The socket t in the back of the slide valve D is squared toreceive and fit the stem D; and passing through the casing and bushing sis a screw h, which extends loosely into the socket 6 to prevent turningof the slidevalve, the stem and pistons on their axes. The screw it thusoperates as a guide and prevents turning of the slide-valves D Z andmaintains their cavities in line with the ports they control. The stem Dextends into a socket g in the piston stem B and is provided at its endin the said socket with a button or stopf. On the stem D near the pistonis is an annular shoulder or stop f; and on the piston B is a plate 9having a recess 9 affording an opening, through which the stem D extendsbetween its stops f and f.

The distance of movement of the .piston B is somewhat in excess of thedistance between the stops f and f whereby as the piston nears the limitof its traverse in the downward direction, the plate g engages the stopf and draws down the stem D; and as the piston nears the limit of itstraverse in the upward direction, the plate or stop g engages the stop fand raises the stem D.

Fig. l' of the drawings shows the piston B on the upstroke, whereby thestop g is moving in the direction of the stop f. The cavity 2' of theslide-valve D registers with the portsp n, causing steam in the chamberA above the piston B to exhaust through the passage n, ports n p,passage 19' and pipe 29 and the port m is uncovered, whereby live steam,entering the chamber 5 from the pipe 0, through the passage 4 and port1", flows through the port 1% and passage m to the chamber A below thepiston B, to raise the latter. The piston and slide-valve Z covers theport (1, leaving the port, Q2 uncovered, whereby steam enters thechamber tabove the piston through the branch passage q and port g andthe slide-valve cavity Z registers with the groove g and port g wherebysteam between the pistons Z and Z0 exhausts to the outside air. Thesteam pressure in the chamber 25 against the upper side of the piston Ztends to hold the parts in the positions shown,

and then through engagement with the latter moves the slide-valve toclose, or nearly close, both the ports n and m. The piston Z .is movedto cover the port g and uncover the port q, and the slide-valve portionof the piston Z is moved to carry its cavity Z above the groove g andcause it to register with the groove (1 and outlet g In the closing ofthe ports n m by the slide-valve D thepressure against the under side ofthe piston B is gradually reduced, and the escape of steam from theupper side of the piston B gradually cut off, whereby the piston comesgradually to a stop, leaving a slight clearance between its upper sideand the adjacent surface of the head A Immediately upon the ports m 'n,being closed, or nearly closed, as described, steam enters the chamber13 through the port q below the piston Z.

The difference in area between the pistons Z and Zc,in favor of theformer, causes predominating pressure to ,be exerted against the pistonZto raise it, the stem D. and attendant parts, until the stops Z impingeagainst the cap as. -When'the piston B thus reaches the upper limit ofits traverse the port g is still covered and the steam in the upper sideof the chamber 6 continues to vent through the groove g cavity Z andoutlet port 9 The slide-valve D uncovers the port n, and through itscavityt' opensicommunication between the ports in 19. Steam entering atthe port 1' will pass through the port at and passage n to the chamber Aabove the piston B, and the steam below the piston B will exhaustthrough the passage m, port m, cavity 11, port 19, passage p and pipe 19This causes the piston B to start immediately on the downward stroke;and, when it nears the limit of its traverse inthat direction, the plateg engages the stopf and moves the stem D in the downward direction. Inthe movement of the stem, brought about by the movement of the piston Bin the downward direction, the pistonZ is caused to overlap and closethe port q and open the port g and the slidevalve portion of the pistonZ is caused to close the outlet from the chamber it, through the grooveg cavity Z and port if, and to open a passage from the under side of thepiston Z, through the groove cavity Z and port The piston 70 is movedinto engagement with the lugs v on the upper side of the slide-valve D,and then by its engagement with the said lugs, movesthe said slide-valveuntil it closes or nearly closes the ports m n, to shut off the supplyof steam to the upper side of the piston B, and the exhaust of steamfrom the under side of said piston, and bring the latter to a gradualstop at a slight distance from the head A to leave the proper clearance.When this movement of the piston Z occurs, as described, steam entersthe chamber t through the port g andowing to the preponderance of itarea of the piston Z over the piston k, moves the stem D, pistons andslide valve D to the positions shown in Fig. 1,whereby the port misuncovered and the port n is opened to the exhaust. t

In practice steam from the port g" g exerts itself against the piston Zto move the slidevalve D immediately upon or slightly in advance of theclosing of the ports m 'n and thus overcomes dead points; and movementof the piston Z under pressure of steam in the chamber 15 follows uponthe movement of the stem D, under engagement of the piston B, so quicklythat there is no appreciable pause in the movement of the slide-valve.In prac tice the steam-pressure may be caused to exert itself againstthe piston Z just before the dead points are reached, so that there isvirtually no pause in the movement of the slidevalve D from the timethat it is started until it reaches the limit of its traverse. Thus thepiston B has a perfectly even stroke and 'comes to a stop at the limitof its traverse without shock.

All the parts employed in the construction of my improved valve-motionare comparatively large and strong,.and little apt to get out of order.By removing the screw cap a: and withdrawing the screw it the entirevalvemotion may be withdrawn through the top of the casing for purposesof cleaning it or for the repair or renewal of any of its parts. Toremove the parts, the piston B is drawn to the top of the chamber A, andthe stem D with its pistons is drawn upward until the stop f reaches theplate g. At such time the small pistonk will be in the chamber 25, and atool may be inserted to. spring the lower part of the stem D to oneside, whereby the button fwill pass through the opening 9 It will thusbe seen that there is no necessity of removing the head A when it isdesired to get at the valve-motion.

While I prefer to construct my improvements in every respect as shownand described, the construction may be lnodifiedin the matter of detailswithout departing from the spirit of my invention asdefined by theclaims.

What I claim as new, and desire to secure by Letters Patent is 1. In afluid-actuated pump, in which the main slide-valve for the main-cylinderports is moved by movement of the main-piston, means for supplementingthe action of the main-piston to carry the main slide-valve beyond thedead-point, comprising, in combination, an auxiliary steam-cylinder,piston and valve, and stop-mechanism connected with and actuated fromthe main-piston and also connected with the auxiliary piston and valve,and operating to open the ports of the auxiliary-cylinder and therebyadvance the auxiliary-piston, and with it the main slidevalve, when thelatter reaches or approximates the dead-point, substantially as de-?scribed.

2. In a fluid-actuated pump, a main-piston,

in a main-cylinder, and auxiliary-piston in an auxiliary-cylindercontrolling ports therein 1 for the admission and exhaust of the fluid,said auxiliary-piston being on a stem presenting stops to themain-piston on opposite sides thereof, the main-piston beingreciprocably movable between the stops on said stem, and a slide-valve,for controlling the fluid inlet and outlet ports of the main-cylinder,positively engaged through themedium of the stem by the main-piston tobe moved, toward the dead-point over the ports it controls, theauxiliary-piston being moved by the stem, in its movement under theaction of the main-piston, to open the fluidsupply to theauxiliary-piston and admit fluid-pressure thereto for continuing itsmotion, thereby supplem eutin g the action of the main-piston to carrythe slide-valve past said dead-point, substantially as described.

3. The combination, with the main steamcylinder, main-piston therein,steam-chamber, steam-induction and exhaust ports and cylinder-ports atsaid chamber, and main slide-valve controlling the supply and exhaust ofsteam through the cylinder-ports, of

an auxiliary steam-cylinder having steam-induction ports and anexhaust-port, an auxiliary-piston in the auxiliary-cylinder operating,when moved initially in either direction, to open one induction-port, todirect steam against one side of the piston, open the piston at itsopposite side to the exhaust and close the other induction-port, wherebythe final movement of the auxiliary-piston in either direction isbrought about by steam entering the auxiliary-cylinder, a stem,connected with the auxiliary-piston, controlling the movement of themain-slide valve, and having stops in the path of the main-piston, theparts being so arranged with relation to each other, that, in the finalmovement of the main-piston, in either direction, it will move the saidstem, to move the main slide-valve. and close, approximately, thecylinder-ports, and move the auxiliary -piston initially, whereby in thefinal movement of the auxiliary-piston, the stem and main slide-valveare moved to open the cylinder-ports, substantially as and for thepurpose set forth.

4. In a steam-actuated pump, the combination, with the steam-cylinder A,and piston B therein, of a chamber 8, at one end of the cylinder, havinga steam-induction port, a", an exhaust-port p, and ports m andn, atopposite sides of the port 19, communicating with opposite ends,respectively, of the cylinder, anauxiliary-cylinder i, havingsteam-induction ports q q -and an exhaust-port g and valve-gear,comprising a stem D, carrying a piston and valve in theauxiliary-cylinder and controlling the ports therein, a main slidevalvein the chambers governing the ports m pm, and actuated by movement ofthe stem, and stops on the stem in the path of the piston B, thevalve-gear being arranged to operate substantially as and for thepurpose set forth.

5. The combination, with the main-cylinder A and main-piston B, of acylinder-head affording a casing, and having an opening through it, fromthe cylinder, closed by a removable cap, and afitording a steam-chambers of small diameter and auxiliary cylinder t of larger diameter, asteam-induction port, an exhaust-port p, and cylinder-ports m and n atopposite sides of the port 19, in the chamber 8, steam-induction ports qand g and an exhaust port g in the auxiliary-cylinder, and valve-gear,comprising a stem D, carrying a piston and valve, in the auxiliarycylinder governing the ports therein, and balanced pistons in oppositeend-portions of the chamber s, a main. slide-valve, between the balancedpistons, governing the ports m 19 n, and actuated by movement of thestem, and stops on the stem in the path of the piston B, the whole beingconstructed and arranged to 0perate substantially as described.

JAMES FARLEY.

In presence of- M. J. FROST, W. U. WILLIAMS.

